Abnormal WBC scattergram: a clue to the diagnosis of malaria

The utility of basic blood counts, WBC histogram and C-reactive protein in detecting malaria

Background

Hematology analyzers display abnormal parameters during malaria infection providing insightful information for suspecting and assessing malaria infection. The goal of this study is to demonstrate the potential of a three-part differential hematology analyzer to assess malaria, provide information about the parasitemia, and discuss the importance of combining C-reactive protein (CRP) with hematology parameters to obtain further information about the malaria infection.

Methods

The present study shows the results of a case–control study during the monsoon season of years 2018 and 2019 in Mumbai, India. The study considers 1008 non-malaria febrile cases, 209 P. vivax and 31 P. falciparum positive malaria samples, five cases of mixed P. vivax and P. falciparum infection, and three co-infection cases of P. vivax and dengue. Raw data from the three-part analyzer LC-667G CRP (HORIBA) and the corresponding microscopic findings (golden standard for diagnosis of malaria) were obtained for each sample.

Results

The medians of platelet counts (PLT) were 102.5, 109.0, and 223.0 × 10³/µL, while CRP medians were 67.4, 81.4 and 10.4 mg/L in P. vivax, P. falciparum and control groups respectively (p < 0.001 in Mann–Whitney U tests between malaria and control groups). Compared with negative samples, platelets counting less than 161.5 × 10³/µL were observed on malaria patients (OR 19.12, 95% CI 11.89–30.75). Especially in P. vivax cases, an abnormal peak was frequently observed in the white blood cells (WBC) histogram around the 37fL channel. The events counted around that channel showed a linear correlation with the counting of red blood cells infected predominantly with larger parasitic forms. Parameters like CRP (rs = 0.325, p < 0.001), WBC (rs = 0.285, p < 0.001) and PLT (rs = − 0.303, p < 0.001) were correlated with the parasitemia of P. vivax samples. Between the malaria and dengue groups, the highest area under the receiver operating characteristic curve was observed on CRP (0.867, CRP ≥ 26.85 mg/L).

Conclusions

A three-part differential hematology analyzer has the potential to not only trigger malaria diagnosis confirmation but also assess the severity of the infection when CRP is considered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06704-5.

Discriminant value of automated leucocyte VCS parameters in the detection of tropical infections

Introduction

In India, infectious diseases are a leading treatable cause of morbidity and mortality. Mangalore being endemic to many vector‐borne diseases, their incidence is known to show seasonal variations with sharp increase during monsoon. Leucocytes have substantial role in the immunological pathogenesis of infections.

Methods

The present series was a hospital‐based cross‐sectional study performed in a tertiary care hospital for a period of three months from June‐August wherein the cell population data of cases of malaria, dengue, leptospirosis, typhoid and rickettsial infections along with equal number of healthy controls were collected and analysed. Effectiveness of leucocyte‐related volume (V), conductivity (C) and scatter (S) parameters by Coulter®DXH800 haematology analyser in predicting these infections was appraised.

Results

A total of 324 cases comprising of malaria (50%), dengue (30.9%), leptospirosis (13.9%), typhoid (4.0%) and rickettsial infections (1.2%) were included. There was statistically significant differences (P < 0.05) in the mean values of complete blood count parameters—haemoglobin, total leucocyte count, red blood cell count, haematocrit, red cell distribution width, differential leucocyte count, platelet count and plateletcrit between cases and controls and also between specific infections. The mean volumes of neutrophil, monocyte and lymphocyte were considerably increased in malaria and dengue fever compared to leptospirosis, typhoid and rickettsial infections. VCS parameters were the least altered in typhoid fever, except for a strikingly high conductivity and scatter of eosinophils.

Conclusions

Haematological analysis is a part of routine evaluation of any case of febrile illness. This study showed that there are specific alterations in VCS parameters in different types of infections such as malaria, dengue, leptospira, typhoid and rickettsia, the information and analysis of which comes without any additional cost.

Mucopolysaccharidosis: A case report highlighting hematological aspects of the disease

A 1½-year-old female child presented with swelling in thoracolumbar region and delayed developmental milestones. The routine hemogram analysis on Sysmex XN 1000 showed flags of white blood cell (WBC) abnormal scattergram and lymphocytosis. The peripheral smear examination showed Alder–Reilly (AR) granules leading to a suspicion of underlying Mucopolysaccharidosis (MPS). Further clinical workup, radiographic studies, chemical test lead to the confirmatory diagnosis of MPS. A flag of abnormal WBC scattergram and AR anomaly are the hematological findings that can be seen in a case of MPS.

M2G1G2 white blood cell flag by three-part automated hematology analyzer: A hint to dengue infection in appropriate clinical context

BACKGROUND

Automated hematology analyzers often generate many flags which can provide important clues to the underlying hematological abnormality. Although pathologists are generally well versed in recognizing the importance of flags indicating potential leukemic blasts, their utility in hinting toward infectious etiology, especially during epidemics, is less well known. We analyzed any abnormal flags generated by a three-part automated hematology analyzer in serologically confirmed cases of dengue.

MATERIALS AND METHODS

The study included 28 patients diagnosed with serologically confirmed dengue infection. The venous samples were run on ABX Miros-60 three-part hematology analyzer. The complete blood count data and any abnormal flags were noted and correlated with peripheral blood film findings in all patients.

RESULTS

An abnormal white blood cell (WBC) flag was noted in all 28 patients, including two in whom all other hematological parameters were within normal limits. In 26 (93%) patients, M2G1G2 WBC flag was noted while the samples of the remaining two patients generated M2G1 and L1M2G1G2 WBC flags, respectively.

CONCLUSION

An abnormal WBC flag, when correlated in appropriate clinical context, especially during a dengue outbreak, can aid in targeting the cohort of patients who will require immediate referral for serological confirmation.

Hematological Profile of Patients Having Malaria-positive Peripheral Blood Smears: A Cross-sectional Study at a Diagnostic Research Center in Khyber Pakhtunkhwa, Pakistan

Malaria is a life-threatening infectious disease that, in severe cases, is associated with calamitous complications and far-reaching consequences within a community. It is usually manifested by abnormalities in various hematological indices with anemia and thrombocytopenia being the most frequent ones. The present study sheds light on the laboratory profile of patients suffering from malaria and provides a comprehensive analysis and correlation with the available literature worldwide. The study was carried out as a cross-sectional study at OK Diagnostic Lab and Research Center in Peshawar from October 2010 to October 2013. All malaria parasite (MP)-positive cases reported at OK Lab during the study period were employed in the study, making a total of 136 MP positive cases. Complete blood pictures with platelet counts were obtained in all patients and various hematological indices were analyzed according to the World Health Organization (WHO) criteria. Thrombocytopenia was defined as a platelet count of < 150 × 103/cmm and anemia as an hemoglobin (Hb) < 13 g/dL in males and < 12 g/dL in females. Among the 136 MP positive patients, 74 (55.4%) had associated thrombocytopenia while 105 (77.2%) patients showed anemia on a peripheral blood smear. This was followed by leukopenia in 8.8% of cases. Among patients with Plasmodium falciparum (P. falciparum) infection, anemia was present in 80% of cases as compared to 74% cases with P. vivax infection (p = 0.5). Thrombocytopenia was associated with P. vivax infection in 71.4% of cases in contrast to P. falciparum infection, where 26% of cases had associated thrombocytopenia (p = 0.01). On the contrary, leukopenia was more prevalent in P. falciparum patients (18%), followed by P. vivax (2.6%), and mixed parasitemia (11.1%) (p < 0.001). In addition, the study showed statistically significant variations in hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and platelet counts across different malarial species (p < 0.05). Likewise, variations within mean Hct levels among males and females were statistically significant, with females showing lower mean Hct levels than males (p < 0.05).

AutomatedPlasmodiumdetection by the Sysmex XN hematology analyzer

Background

Malaria is a potentially severe disease affecting nearly 200 million people per year. Early detection of the parasite even in unsuspected patients remains the challenging aim for effective patient care. Automated complete blood counts that are usually performed for any febrile patient might represent a tool to ascertain malaria infection.

Aims

To evaluate the ability of the new generation of the Sysmex hematology analyzer (XN-series) to detect malaria.

Methods

We retrospectively studied 100 blood samples performed with the recent Sysmex XN analyzer that were positive forPlasmodiumand explored its ability to detect the parasite. 100 samples from patients uninfected by malaria were used as control group.

Results

Specific abnormalities such as additional events in the mature neutrophil/eosinophil area of the white blood cells differential (WDF) scattergram were noted for 1.1% ofPlasmodium falciparumsamples and 56.2% of otherPlasmodiumspecies samples. Mature parasite stages (schizonts or gametocytes) were observed on blood smears among those samples. WDF scattergrams were able to detect 80.0% (12/15) ofPlasmodiummature stages. Furthermore, the differential in white blood counts between WDF and white cell nucleated (WNR) channels was a predictive signal ofPlasmodiummature stages in 73.3% (11/15) of samples and may be explained by a differential destruction of particles with the analyzer reagent.

Conclusion

Associated to thrombocytopaenia, a Sysmex XNPlasmodiumpattern may represent a useful warning forPlasmodiumdetection in unsuspected patients, particularly when mature parasite stages are present.

Source identification of autochthonous-introduced Plasmodium vivax Malaria, Spain

In 2014, an autochthonous case of introduced malaria caused by Plasmodium vivax was identified in Spain. The strain that infected this patient was identical to that of a prior imported case from Pakistan. This is the first case where the source of infection could be identified since elimination in Spain.

Automated Hematology Analyzers in Diagnosis of Plasmodium vivax Malaria: an Adjunct to Conventional Microscopy

Malaria is one of the most pervasive parasitic diseases ever known to mankind affecting nearly 300 million people every year. The need for rapid diagnosis of malaria in tropical and subtropical malaria endemic areas is on the rise. In this study, we evaluated the usefulness of hematology autoanalyzers, Sysmex XE-2100 & XT-2000i in the presumptive diagnosis of malaria. Our study shows that abnormalities in WBC/BASO scattergram when combined with presence of thrombocytopenia had a high sensitivity and positive predictive value in the presumptive diagnosis of Plasmodium vivax (P.vivax) malaria.

Guideline: the laboratory diagnosis of malaria. General Haematology Task Force of the British Committee for Standards in Haematology

UK National External Quality Assessment Service surveys indicate continuing problems in malaria diagnosis: inaccurate calculation of parasitaemia or failure to estimate it altogether, difficulty distinguishing Plasmodium vivax from P. ovale, reporting malaria parasites when none were present and misidentification of P. falciparum as another species still occur. Therefore, the British Committee for Standards in Haematology Guidelines for the Laboratory Diagnosis of Malaria have been revised. They are intended for use in the UK but may also prove useful in other non-endemic areas. Routine use of thick and thin films is advised for malaria diagnosis. Thick films should be stained using Giemsa or Field stain. Thin films should be stained with Giemsa stain or Leishman stain. Thick films should be examined by two observers, each viewing a minimum of 200 high power fields. If thick films are positive, the species should be determined by examination of a thin film. In the case of P. falciparum or P. knowlesi infection, the percentage of parasitized cells or the number of parasites per microlitre (/μl) should be estimated and reported. Rapid diagnostic tests (RDTs) for malarial antigen cannot replace microscopy but are indicated as a supplementary test when malaria diagnosis is performed by relatively inexperienced staff. Malaria RDTs are negative in babesiosis.